This is my first time using a canister filter. I purchased one awhile ago and could not get it to work. I contacted Marineland who gave me various advice, as follows:

Initially, I couldn't get it to suck in the water from the tank and this was after priming it for about an hour.
ML response: Fill the canister at least 3/4 of the way full of water.

I filled it with water as they suggested and it still wouldn't suck in the water. Water went out the outtake in a trickle.
ML response: They would send me a new impeller in case the one in the box was too weak.

I received the impeller in about a week, switched it out and had the same problem.
ML response: It's under warranty and they were going to send me a replacement.

I received the replacement today and set up the new canister and am having the same problem as before...the water will not come down the intake tube into the canister. And no water is going out of the outtake, even the water in the canister placed there by me, even though I see some trying to go through the tube when I prime and/or plug in the canister.

I am at a loss. Both my husband and I have tried to get this thing to work, and my dad took a look as well. I'm willing to admit the problem lies with us, but I don't know what to do to get this thing to work. Does anyone have experience with these and might have some advice?